You'll use this file browser every day, so I'll give you a couple of tips to
use it at best. First of all, ask your sysadm to configure less so as
it can display not only plain text files, but also compressed files,
archives, and so on.

The main advantage of less over TYPE is that you can browse files
in both directions. It also accepts several commands that are issued
pressing a key. The most useful are:

first of all, press q to leave the browser;

h gives you extensive help;

g to go to beginning of file, G to the end, number+g
to go to line `number' (e.g. 125g), number+% to move to that
percentage of the file;

The lack of version numbers in files can be easily overcome by using RCS
(Revision Control System). This allows you to maintain several versions of
the same file, and offers many more advantages. I'll only explain the very
basics of this powerful version control system.

The most important commands are ci and co. The first (``check
in'') is used to commit the changes you have done to your file, and create a
new version. The second (``check out'') is used to obtain a working copy of
your file from the RCS system, either to modify it or simply use it for
browsing, printing, or whatever.

Let's see an example. First of all you create an initial revision of
your file, using your favourite editor. Let's suppose that the file you'll
have under RCS control is called project.tex. Follow these steps:

make a subdirectory called RCS/ in the directory containing
project.tex. RCS/ will contain the revision control file;

to put project.tex under RCS control, issue the command

$ ci project.tex
RCS/project.tex,v <-- project.tex
enter description, terminated with a single '.' or end of file:
NOTE: This is NOT the log message!
>>

you will write a line or more containing a description of the
contents of your file. End it with a line containing a '.' by itself, and
you'll see

initial revision: 1.1
done

Now the file project.tex has been taken over by RCS.

Using the latest version

Whenever you want to use, but not modify, the latest version of project.tex,
you issue the command

$ co project.tex
RCS/project.tex,v --> project.tex
revision 1.1
done

This extracts the latest version (read only) of your file. Now you can browse
it, or compile it with tex, but you can't modify it.

Creating a new version

When you want to modify your file, you must obtain a ``lock'' on it. This
means that RCS knows that you're about to make a newer version. In this
case, you use the command

Under UNIX there are some widely used applications to archive and
compress files. tar is used to make archives, that is collections of
files. To make a new archive:

$ tar -cvf <archive_name.tar> <file> [file...]

To extract files from an archive:

$ tar -xpvf <archive_name.tar> [file...]

To list the contents of an archive:

$ tar -tf <archive_name.tar> | less

Files can be compressed to save disk space using compress, which is
obsolete and shouldn't be used any more, or gzip:

$ compress <file>
$ gzip <file>

that creates a compressed file with extension .Z (compress) or .gz
(gzip). These programs don't make archives, but compress files
individually. To decompress, use:

$ compress -d <file.Z>
$ gzip -d <file.gz>

RMP.

The unarj, zip and unzip utilities are also available. Files
with extension .tar.gz or .tgz (archived with tar, then
compressed with gzip) are very common in the UNIX world. Here's how to
list the contents of a .tar.gz archive: